Mild decrease in heart rate during early phase of targeted temperature management following tachycardia on admission is associated with unfavorable neurological outcomes after severe traumatic brain injury: a post hoc analysis of a multicenter randomized controlled trial

Abstract

BackgroundThe association between isolated admission heart rate (HR) and prognosis has been discussed, but not that between gross HR change and neurological outcome in patients with severe traumatic brain injury (TBI). In the acute phase of severe TBI, HR is influenced by several factors (e.g., pain, sympathetic activation, hypovolemia, fever, body temperature). Therefore, admission HR and gross HR change should be examined in patients with TBI treated with a well-designed protocol, such as was done in the Brain Hypothermia (B-HYPO) Study.MethodsThis was a post hoc analysis of the B-HYPO Study, which was conducted as a prospective, multicenter, randomized controlled trial in patients with severe TBI receiving mild therapeutic hypothermia (MTH; 32.0 °C–34.0 °C) or fever control (35.5 °C–37.0 °C) in Japan. Patients with MTH were examined, and HR change (%HR) in the early MTH phase was calculated as follows: [admission HR – HR at day 1]/admission HR × 100. Patients were divided into six groups, using admission HR (< 80, 80–99, ≤ 100) and median of %HR; i.e., group (Admission HR < 80 and %HR ≥ 18.6); group (Admission HR < 80 and %HR < 18.6); group (Admission HR 80–99 and %HR ≥ 18.6); group (Admission HR 80–99 and %HR < 18.6); group (Admission HR ≥100 and %HR ≥ 18.6); and group (Admission HR ≥100 and %HR < 18.6). The primary outcome was an adjusted predicted probability of unfavorable neurological outcome at 6 months after TBI according to Glasgow Outcome Scale score, which is a measure of functional recovery and defined as severe disability, persistent vegetative state, and death.ResultsOverall, 79 patients with MTH (52.7% of the original trial) were examined; among these, unfavorable neurological outcomes were observed in 53.2%. Among all the groups, group (Admission HR ≥100 and %HR < 18.6) exhibited the highest proportion of unfavorable outcomes, and 82.3% of patients had an adjusted predicted probability of unfavorable outcomes, whereas those in group (Admission HR < 80 and %HR ≥ 18.6) developed only 22.8% (p = 0.04).ConclusionsMild HR decrease during the early phase of targeted temperature management following tachycardia at admission can be associated with unfavorable neurological outcomes after severe TBI.Electronic supplementary materialThe online version of this article (10.1186/s13054-018-2276-6) contains supplementary material, which is available to authorized users.

Prediction of in-hospital mortality in patients on mechanical ventilation post traumatic brain injury: machine learning approach

“…Tachycardia (HR > 100 bpm), in patient with trauma, could be an indicator of hypovolemic shock that may negatively impact the CPP. This negative effect worsens when tachycardia is associated with low SBP (< 90 mmHg) which leads to poor TBI outcomes [ 38 , 41 ]. The mean HR upon admission to the emergency room following TBI was 102.8 beats per min while the mean HR upon arrival for those who died was 107.7 beats per minute.…”

Prediction of in-hospital mortality in patients with post traumatic brain injury using National Trauma Registry and Machine Learning Approach

“…Further, presenting heart rate (HR) is an indicator of the patient's hemodynamic stability following any type of trauma particularly TBI. High HR (> 100 bpm) [42] especially when associated with Low SBP (< 90 mmHg) [40] may indicate hypovolemic shock state which leads to poor CPP. This study found a positive relationship between the HR and in-hospital mortality.…”

Targeted temperature management guided by the severity of hyperlactatemia for out-of-hospital cardiac arrest patients: a post hoc analysis of a nationwide, multicenter prospective registry

“…To obtain the adjusted predicted probabilities of 30-day favorable neurological outcome and 30-day survival, we used multiple logistic regression model adjusted for age > 65 [21, 22], gender [21, 23], witness [24], dispatcher instruction [25, 26], bystander CPR [24, 27], cardiac etiology [28], initial shockable rhythm [29, 30], prehospital epinephrine administration [31], prehospital advanced airway management [32], time from call to hospital arrival [33, 34], prehospital ROSC [35, 36], Glasgow Outcome Scale score [37], coronary angiography [38], extracorporeal membrane oxygenation (ECMO) and/or intra-aortic balloon pumping (IABP) [22, 39], and PaCO 2 30–50 mm Hg [40, 41], as performed in previous studies [23, 42].…”